JP6277948B2 - Lower body structure of automobile - Google Patents

Description

  The present invention includes a tunnel portion formed in the center of the floor panel in the vehicle width direction and extending in the front-rear direction of the vehicle, left and right side sills formed in the left and right side portions of the floor panel and extending in the front-rear direction of the vehicle, The present invention relates to a lower body structure of an automobile provided with left and right center pillars extending from a side sill in a vehicle vertical direction.

  In general, in a lower body structure of an automobile, a cross member extending in the vehicle width direction is installed between a side sill near a center pillar and a tunnel portion, and another cross member is horizontally mounted in front of the cross member. Thus, a seat rail support structure is employed in which the seat rail is supported by both the front and rear cross members.

  Since the above-described structure requires two cross members, conventionally, in order to reduce the weight of the vehicle, one cross member extending in the vehicle width direction is provided between the side sill near the center pillar and the tunnel portion. There is a construction in which a seat rail mounting seat is separately provided on a floor panel or a tunnel portion, and the seat rail is mounted and supported on a cross member and a seat rail mounting seat.

  In this conventional structure, there is an advantage that the weight of the vehicle can be reduced by changing the number of cross members from two to one, but the range in which the tunnel portion is not supported by the frame structure is enlarged, and the cross member is expanded. There is a problem in that the opening deformation of the tunnel portion before and after the member becomes large, thereby generating noise and impairing the quietness in the passenger compartment.

  Therefore, a structure in which the bracket that forms the seat rail mounting seat is extended in the front-rear direction and the movement of the tunnel portion is suppressed by the bracket is considered, but the weight of the vehicle body has been reduced by unifying the cross member. Regardless, there is room for improvement because the weight of the vehicle body increases due to the lengthening of the bracket in the longitudinal direction.

  By the way, in Patent Document 1, the front part of the seat rail is attached to and supported by a cross member constructed between the side sill and the tunnel part, and the rear part of the seat rail is attached to a seat rail mounting seat provided in the tunnel part. A supporting arrangement is disclosed.

  In the conventional structure disclosed in Patent Document 1, the opening deformation of the tunnel portion at a position corresponding to the lower portion of the center pillar is larger than the conventional structure using two cross members, and noise is worsened. There was a problem.

JP2013-103528A

  Thus, as a result of repeating various kinds of experiments, the present inventors have found that when the cross member is integrated, the tunnel portion moves in reverse phase around the cross member. The inventors have invented the present application paying attention to the reverse phase movement of the tunnel portion.

  That is, according to the present invention, by integrating the cross member, the weight is reduced and the opening deformation before and after the tunnel portion is reversed, and the vibration of the opposite phase deforms the seat rail rigidly coupled to the seat rail mounting seat. An object of the present invention is to provide a lower body structure of an automobile that can suppress such vibrations with a seat rail having high rigidity and can improve the quietness with light weight and high rigidity.

The lower body structure of an automobile according to the present invention includes a tunnel portion formed in the center of the floor panel in the vehicle width direction and extending in the vehicle front-rear direction, and a left and right side formed in the left and right sides of the floor panel and extending in the vehicle front-rear direction. A vehicle body structure including a side sill and left and right intermediate pillars extending in the vehicle vertical direction from the left and right side sills, between the side sill near the intermediate pillar and the tunnel portion in a vehicle width direction. One extending cross member is installed in direct contact with the panel-shaped side wall of the tunnel portion , and is positioned below the corner portion on the upper wall of the tunnel portion at a position spaced from the cross member in the front-rear direction. seat rails mounting seat to the side wall lower a lower portion of the side wall is provided for, the seat rail mounting seat, the tunnel portion and the upper The separate member from the cross member, front and a wall and a rear wall and side walls and top wall, is formed in the opening shape downward, the seat rail mounting seat from the front mounting seat and rear mounting seats made, from the junction between the tunnel portion of the cross member, spaced forwardly to a position where the mouth apertures closed deformation of the tunnel portion side wall is increased, and the front mounting locus the tunnel portion spaced with the cross member The front mounting seat is joined to the floor panel and below the corner portion of the tunnel portion on the upper wall of the tunnel portion, and at the lower portion of the side wall where the mouth opening deformation is larger than the corner portion. are joined, the junction between the tunnel portion of the cross member, the mouth open mouth close variant of the tunnel portion side walls spaced rearwardly from greater a position above the front mounting seat opposite phase, the Side mounting After separated from the Rosumenba locus is joined to the said tunnel portion and the floor panel, and below the corner of the upper wall of the tunnel portion of the tunnel portion, the mouth apertures closed deformation than the corner portion There the rear mounting seat is joined to the lower side wall to be greater in the front mounting seat opposite phase, the bottom surface of the rear end portion of the seat rail is rigidly coupled to face the upper wall of the rear mounting seat Is.
The intermediate pillar described above may be a center pillar.

  According to the above configuration, one cross member extending in the vehicle width direction is installed between the side sill in the vicinity of the center pillar and the tunnel portion. The reverse phase of the mouth opening deformation is aimed at.

  A seat rail mounting seat is provided at least at the lower portion of the tunnel portion at a position where the deformation becomes large in the opposite phase, that is, at a position separated from the cross member in the front-rear direction, and the bottom surface of the seat rail is rigidly coupled to the seat rail mounting seat. Therefore, the anti-phase vibrations before and after the cross member act to deform the seat rail rigidly connected to the seat rail mounting seat. However, the seat rail has high rigidity and high proof stress. Vibrations can be suppressed.

  Accordingly, the seat structure itself can be used without reinforcing the vehicle body itself, and light weight and high rigidity can be enhanced.

  In one embodiment of the present invention, the upper portions of the left and right intermediate pillars are connected to a roof reinforcement extending in the vehicle width direction along the lower portion of the roof panel.

  According to the above configuration, an annular frame structure can be formed by the roof reinforcement, the left and right center pillars, and the cross member, thereby ensuring a structure that is more resistant to torsion of the vehicle body. it can.

  In one embodiment of the present invention, a tunnel reinforcement is provided on the upper surface of the front portion of the tunnel portion, and the rear portion of the tunnel reinforcement is rigidly connected to the front seat rail mounting seat. It is.

  According to the said structure, a tunnel vibration suppression area | region can be expanded ahead of a vehicle by the rigid body coupling | bonding of a tunnel reinforcement and a seat rail attachment seat.

  According to the present invention, by unifying the cross member, the weight is reduced and the opening deformation before and after the tunnel portion is reversed, and the vibration of the opposite phase deforms the seat rail rigidly coupled to the seat rail mounting seat. Thus, there is an effect that the vibration is suppressed by the seat rail having high rigidity, and the quietness can be improved with light weight and high rigidity.

The perspective view which shows the lower vehicle body structure of the motor vehicle of this invention Lower body structure and exploded perspective view of seat 1 is an enlarged perspective view of the main part of FIG. 3 is an enlarged perspective view of the left side of the vehicle in FIG. 3 is a cross-sectional view taken along line AA in FIG. BB cross-sectional view of FIG. (A) is a perspective view of a front seat rail mounting seat, (b) is a perspective view of a rear seat rail mounting seat. Characteristic diagram showing sound pressure characteristics with respect to frequency

By unifying the cross member, the weight is reduced and the opening deformation before and after the tunnel part is reversed, and the vibration of this opposite phase works to deform the seat rail rigidly connected to the seat rail mounting seat. For the purpose of suppressing such vibration with a high seat rail, light weight, high rigidity and quietness, a tunnel portion formed in the center of the floor panel in the vehicle width direction and extending in the front-rear direction of the vehicle, A vehicle lower body structure comprising left and right side sills formed on both sides and extending in the longitudinal direction of the vehicle, and left and right intermediate pillars extending in the vehicle vertical direction from the left and right side sills, between the side sill and the tunnel portion, one cross member extending in the vehicle width direction, is spanned by joining directly with the panel side wall of the tunnel portion, the Kurosumen Seat rails mounting seat to the side wall lower a lower portion of the side wall below the corners of the upper wall of the tunnel portion of the tunnel portion is provided in a position spaced apart in the longitudinal direction from the seat rail mounting seat, the A member different from the tunnel part and the cross member is formed in a shape having a front wall, a rear wall, a side wall, and an upper wall and opened downward. The seat rail mounting seat includes a front mounting seat and a rear side. The front mounting seat separated from the cross member is configured to be separated from the joint portion of the cross member with the tunnel portion and forwardly to a position where the opening and closing deformation of the side wall of the tunnel portion becomes large. is joined to the aforementioned tunnel section and the floor panel, and below the corner of the upper wall of the tunnel portion of the tunnel portion, the mouth than the corner portion In the side wall lower mouth closed deformation can increase, the front mounting seat is joined, from the junction between the tunnel portion of the cross member, the tunnel portion side wall of the mouth apertures closed deformation the front mounting seat and reverse phase in spaced rearwardly until larger position, is bonded to and the said floor panel side mounting locus the tunnel portion after separated from the cross member, and than the corner portion of the upper wall of the tunnel portion of the tunnel portion The rear mounting seat is joined to the lower portion of the side wall, the lower opening of which is more deformed in the opposite phase to the front mounting seat, and the bottom surface of the rear end portion of the seat rail is the rear side. Realized by a rigid body connection facing the upper wall of the mounting seat.

An embodiment of the present invention will be described in detail with reference to the drawings.
The drawings show a lower body structure of an automobile, FIG. 1 is a perspective view of the body structure of the automobile including the lower body structure, FIG. 2 is an exploded perspective view of the lower body structure and seat, and FIG. 4 is an enlarged perspective view of the left side of the vehicle in FIG. 3, FIG. 5 is a sectional view taken along line AA in FIG. 3, and FIG. 6 is a sectional view taken along line BB in FIG.

  1, 2, and 3, a floor panel 10 (specifically, a front floor panel) that forms the floor surface of the passenger compartment is provided, and the vehicle protrudes into the passenger compartment at the center of the floor panel 10 in the vehicle width direction. A tunnel portion 11 extending in the front-rear direction is formed.

  In this embodiment, as shown in FIG. 6, the floor panel 10 and the tunnel portion 11 are formed by separate members, but the present invention is not limited to this, and the tunnel portion 11 and the floor panel 10 are integrally formed. May be.

  As shown in FIG. 6, the left and right side walls 11 a and 11 b of the tunnel portion 11 are extended further downward than the height position of the floor panel 10, and the left and right lower edges of the tunnel portion 11 are substantially concave in the vehicle front view. A tunnel lower edge groove 14 having a bottom wall 12 and a joining flange 13 with the floor panel 10 is formed.

  The above-described tunnel portion 11 extends in the vehicle front-rear direction from the dash lower panel to the rear cross member (so-called No. 3 cross member), and on the front upper surface of the tunnel portion 11, A tunnel reinforcement 16 (so-called high-mount backbone frame) having two ridges 15 and 15 extending in the longitudinal direction of the vehicle along the upper surfaces of the corner portions 11d and 11e is integrated by a welding means such as spot welding. A closed cross section 17 extending in the front-rear direction of the vehicle is formed between the tunnel reinforcement 16 and the tunnel portion 11.

  As shown in FIGS. 1 to 3, the tunnel reinforcement 16 described above extends in the vehicle front-rear direction from the dash lower panel to the position where the center console mounting bracket is disposed.

  The rigidity of the tunnel portion 11 should be improved by both the closed section 17 between the tunnel section 11 and the tunnel reinforcement 16 and the substantially concave closed section of the tunnel lower edge groove 14. It is composed.

As shown in FIGS. 1 and 3, side sills 18 are bonded and fixed to the left and right sides of the floor panel 10.
As shown in FIG. 3, the side sill 18 is a vehicle body strength member that includes a side sill closed section 22 that joins a side sill inner 19, a side sill outer 20, and a side sill reinforcement 21 and extends in the front-rear direction of the vehicle.

  As shown in FIG. 1, the above-described side sill 18 extending in the vehicle front-rear direction at the lower part of the vehicle and the roof side rail 23 extending in the vehicle front-rear direction at the upper part of the vehicle are provided. The space is connected in the vertical direction by a front pillar (not shown) and a hinge pillar 24 shown in FIG.

  The hinge pillar 24 is a vehicle body strength member in which a hinge pillar inner section 25, a hinge pillar outer, and a hinge pillar reinforcement are joined and fixed to form a hinge pillar closed section extending in the vertical direction of the vehicle. Only 25 is shown.

Further, as shown in FIG. 1, an intermediate portion in the vehicle front-rear direction between the roof side rail 23 and the side sill 18 is connected in the vertical direction by a center pillar 26 as an intermediate pillar.
As shown in FIG. 3, the center pillar 26 includes a center pillar inner section 27, a center pillar outer 28, and a center pillar reinforcement 29 that are joined and fixed to each other, and has a center pillar closed section 30 that extends in the vertical direction of the vehicle. It is a strength member.

  Further, as shown in FIG. 1, the rear end portions of the roof side rail 23 and the side sill 18 are connected in the vertical direction by a rear pillar 31 having a closed cross-sectional structure.

As shown in FIG. 1, an opening surrounded by the side sill 18, the center pillar 26, the roof side rail 23, the front pillar, and the hinge pillar 24 (see FIG. 4) is formed on the vehicle body side portion. Is set.
In addition, an opening surrounded by the side sill 18, the center pillar 26, the roof side rail 23, and the rear pillar 31 is set as a rear door opening 33 on the side of the vehicle body.

  In FIG. 1, for convenience of illustration, the center pillar 26, the roof side rail 23, and the rear pillar 31 are illustrated only for the left side of the vehicle, but there are a pair of left and right elements 26, 23, and 31 on the left side and the right side of the vehicle. Is.

  As shown in FIG. 1, the upper portions of the left and right center pillars 26 are connected to a roof reinforcement 34 that extends in the vehicle width direction along the lower portion of a roof panel (not shown). That is, both ends in the vehicle width direction of the roof reinforcement 34 are joined and fixed to the roof side rail 23, while the upper end of the center pillar 26 is joined and fixed to the roof side rail 23. It is connected via a roof side rail 23.

  As described above, the upper part of the left and right center pillars 26, 26 is connected to the roof reinforcement 34 extending in the vehicle width direction along the lower part of the roof panel (not shown). The center pillars 26, 26 and a cross member 35, which will be described later, can form an annular frame structure, thereby ensuring a structure that is strong against torsion of the vehicle body.

By the way, the lower body structure of the automobile of this embodiment is formed in the tunnel portion 11 formed at the center in the vehicle width direction of the floor panel 10 and extending in the front-rear direction of the vehicle, and on both the left and right sides of the floor panel 10. Side sills 18 and 18 extending in the longitudinal direction of the vehicle, and left and right center pillars 26 and 26 extending from the left and right side sills 18 and 18 in the vehicle vertical direction, as shown in FIGS. Thus, a cross member 35 (so-called No. 2 cross member) extending in the vehicle width direction is installed between the side sill 18 in the vicinity of the center pillar 26 and the tunnel portion 11, and the cross member 35 and the floor are A closed cross section 36 extending in the vehicle width direction is formed between the panel 10 and the panel 10 as shown in FIG.
The above-mentioned cross member 35 is preferably arranged at the root portion of the center pillar 26 in order to efficiently transmit the side collision load.

  As shown in FIG. 5, the cross member 35 is formed in a hat shape in cross section, and the joining flange portions 35 a and 35 b located on both the front and rear sides of the lower end portion are joined and fixed to the floor panel 10, and the cross member 35. Are joined and fixed to the corresponding side wall 11a or side wall 11b of the tunnel portion 11 and the plurality of joint flange portions 35c, 35d, 35e located at the inner end in the vehicle width direction.

  Also, as shown in FIGS. 3 and 4, a plurality of joint flange portions 35f, 35g, and 35h are integrally formed at the outer end portion of the cross member 35 in the vehicle width direction, and the plurality of joint flange portions 35f, 35g. , 35 h are joined and fixed to the side sill inner 19.

  For the purpose of reducing the weight of the vehicle, when the one cross member 35 is installed between the side sill 18 near the center pillar 26 and the tunnel portion 11 and the cross member 35 is unified, FIG. As shown in FIG. 4, when the tunnel portion 11 on the front side of the cross member 35 is deformed in the closing direction as indicated by a dotted arrow a in FIG. When the tunnel portion 11 in front of the cross member 35 is deformed in the direction of opening as shown by an imaginary arrow c in FIG. 4, the rear side of the cross member 35 is deformed. The tunnel portion 11 is deformed in the mouth closing direction as indicated by the phantom arrow d in FIG.

That is, the tunnel portion 11 moves in the opposite phase before and after the cross member 35, and vibration is generated and noise is generated due to the opposite phase movement of the opening deformation. This suppresses the movement of the opposite phase.
Since the lower body structure of the automobile of this embodiment is substantially symmetrical, the configuration on the left side of the vehicle will be mainly described. The configuration on the right side of the vehicle is denoted by the same reference numerals as those on the left side of the vehicle.

  As shown in FIG. 4, the front side as a seat rail mounting seat is provided at least at the lower portion of the tunnel portion 11 at a position where the movement in the reverse phase is as large as possible, away from the single cross member 35 described above. A mounting seat 41 and a rear mounting seat 42 are provided, and a front mounting seat 43 is provided on the side sill inner 19 so as to face the front mounting seat 41 in the vehicle width direction. Opposite to the vehicle width direction, the side sill inner 19 is provided with a rear mounting seat 44 on the outer side in the vehicle width direction.

  The reason why the front mounting seat 41 and the rear mounting seat 42 described above are provided at least in the lower part of the tunnel portion 11 is that the side walls 11a and 11b of the tunnel portion 11 have the corners 11d and 11e of the tunnel portion 11 as fulcrums and the opening direction. This is because the deformation is caused in the closing direction, and the vibration caused by the deformation becomes large at the lower portion of the tunnel portion 11.

As shown in FIG. 3, the front and rear mounting seats 43, 44 on the outer side in the vehicle width direction have a substantially box shape with the lower side and the outer side in the vehicle width direction opened, and the front mounting seat 43 and the rear side mounting seat Joining flange portions 43a, 43b, 43c, 44a, 44b, 44c, and 44d are integrally formed on the seat 44, and the joining flange portions 43a, 43b, 44a, and 44b among these joining flange portions are floor panels. The other flange portions 43 c, 44 c, 44 d are joined and fixed to the side sill inner 19.
A bracket 45 is joined and fixed to an upper portion of the front mounting seat 43 located on the vehicle front side of the front and rear mounting seats 43 and 44 on the outer side in the vehicle width direction.

7A is a perspective view of the front mounting seat 41, and FIG. 7B is a perspective view of the rear mounting seat 42. FIG.
As shown in FIG. 7 (a), the front mounting seat 41 has a front wall 41a, a rear wall 41b, a side wall 41c, and an upper wall 41d, with the lower side and the inner side in the vehicle width direction being open. A plurality of joint flange portions 41e, 41f, 41g, 41h, 41i, and 41j are integrally formed while being formed in a box shape.

As shown in FIG. 4, a bracket 46 is provided so as to close the tunnel lower edge groove 14 corresponding to the attachment portion of the front attachment seat 41. As shown in FIGS. 4 and 6, the inner end bent portion 46 a of the bracket 46 in the vehicle width direction is joined and fixed to the lower portions of the side walls 11 a and 11 b of the tunnel portion 11, and the outer end portion of the bracket 46 in the vehicle width direction is It is fixedly bonded to the floor panel 10.
The above-described bracket 46 is bridged over the tunnel lower edge groove 14 so that the tunnel lower edge groove 14 is closed with a high rigidity to suppress vibration in the vehicle width direction of the side walls 11a and 11b of the tunnel portion 11. doing.

  As shown in FIGS. 4 to 7, among the plurality of joint flange portions 41 e to 41 j of the front mounting seat 41, the joint flange portion 41 i is joined and fixed to the floor panel 10, and the joint flange portions 41 f and 41 h are brackets 46. The joint flange portions 41e and 41g are joined and fixed to the side wall 11a or the side wall 11b of the tunnel portion 11, and the joint flange portion 41j is connected to the tunnel reinforcement 16 as shown in FIG. The rear part and the side wall 11a or 11b of the tunnel part 11 are rigidly connected by a three-piece welding means.

In this embodiment, as shown in FIG. 4, the joint flange portion 41j is rigidly connected to the elements 16 and 11 at the front and rear points at spot welding points sw1 and sw2.
In particular, the joint vibration portion 41j of the front mounting seat 41 is rigidly coupled to the tunnel reinforcement 16 so that the tunnel vibration suppression region is expanded forward of the vehicle.

  On the other hand, as shown in FIG. 7B, the rear mounting seat 42 has a front wall 42a, a rear wall 42b, a side wall 42c, and an upper wall 42d. It is formed in an open substantially box shape, and a plurality of joining flange portions 42e, 42f, 42g, 42h, 42i, 42j are integrally formed.

As shown in FIGS. 4, 5, and 7, among the plurality of joining flange portions 42 e to 42 j of the rear mounting seat 42, the joining flange portion 42 i is joined and fixed to the floor panel 10. 42h is joined and fixed to the tunnel lower edge groove 14, and the other joined flange portions 42e, 42g, and 42j are joined and fixed to the side wall 11a or the side wall 11b of the tunnel portion 11.
In particular, the front wall 42a and the rear wall 42b having the above-described joint flange portions 42f and 42h are set as legs extending downward to the inner bottom portion of the tunnel lower edge groove 14, and the joint flange portions 42f and 42h and the tunnel lower edge groove are formed. 14, the tunnel lower edge groove 14 is reinforced to suppress the swinging in the vehicle width direction.

  Here, the front mounting seat 41 may be formed in the same manner as the rear mounting seat 42 as long as the rigidity in the front-rear direction of the cabin and the seat support rigidity at the time of the frontal collision of the vehicle can be satisfied.

  Thus, at a position spaced from the cross member 35 in the vehicle front-rear direction, a front mounting seat 41 and a rear mounting seat 42 are provided at least at the lower portion of the tunnel portion 11, and the mounting seats 41, 42 are provided. The bottom surface of the lower rail 50 as a seat rail is rigidly coupled to the upper walls 41d and 42d via spacers 47 and 48 shown in FIGS.

  As shown in FIG. 6, the front end portion of the lower rail 50 is fastened to the spacer 47 and the front mounting seat 41 together by using two sets of mounting members 49 such as bolts and nuts arranged in the longitudinal direction of the lower rail 50. Thus, the bottom surface of the lower rail 50 is rigidly connected to the upper wall 41d of the front mounting seat 41 through the spacer 47 so as to make surface contact. By rigidly coupling the front end portion of the lower rail 50 to the front mounting seat 41 using two sets of mounting members 49, 49, the lower rail 50 is configured to reliably receive the torsion of the mounting seat 41.

  Similarly, the rear end portion of the lower rail 50 is also fastened to the spacer 48 and the rear mounting seat 42 by using two sets of mounting members (not shown) such as bolts and nuts arranged in the longitudinal direction of the lower rail 50. In addition, the bottom surface of the lower rail 50 is rigidly coupled to the upper wall 42d of the rear mounting seat 42 through the spacer 48 so as to make surface contact. Then, the rear end portion of the lower rail 50 is rigidly connected to the rear side mounting seat 42 using two sets of mounting members in the same manner as the front end portion, so that the twisting of the mounting seat 42 is reliably received by the lower rail 50. doing.

  Here, instead of the configuration in which the bottom surface of the front end and the bottom surface of the rear end of the lower rail 50 are brought into surface contact with the upper wall 41d of the front mounting seat 41 and the upper wall 42d of the rear mounting seat 42 via the spacers 47 and 48, respectively. The above-described spacers 47 and 48 are omitted, and a structure is adopted in which the bottom surfaces of both the front and rear portions of the lower rail 50 are in direct surface contact with the upper wall 41d of the front mounting seat 41 and the upper wall 42d of the rear mounting seat 42. May be.

  A pair of front and rear mounting seats 41 and 42 on the inner side in the vehicle width direction and a pair of front and rear mounting seats 43 and 44 on the outer side in the vehicle width direction facing the vehicle width direction are attached to a seat using mounting members such as bolts and nuts (not shown). A lower rail 51 as a rail is coupled and fixed.

  As described above, one cross member 35 extending in the vehicle width direction is installed between the side sill 18 near the center pillar 26 and the tunnel portion 11, and the weight of the vehicle is reduced by integrating the cross member 35. And the opening part deformation before and after the tunnel part 11 is reversed, and the lower rail 50 is attached to at least the lower part of the tunnel part 11 at a position where the deformation becomes larger in the opposite phase, that is, at a position spaced from the cross member 35 in the front-rear direction. Front and rear mounting seats 41 and 42 are provided, and the bottom surface of the lower rail 50 is rigidly coupled to the front and rear mounting seats 41 and 42. The reverse-phase vibrations before and after the cross member 35 act to deform the lower rail 50 rigidly connected to the front and rear mounting seats 41 and 42. However, the lower rail 50 has high rigidity and high proof strength, so the lower rail 50 is twisted. There is nothing, and vibration can be suppressed.

  Accordingly, the seat structure itself is used without reinforcing the vehicle body itself, and the existing lower rail 50 is used to increase the number of parts without increasing the number of parts, and is configured to be light and highly rigid and quiet. Is.

  As shown in FIG. 2, a front seat 60 is attached to the above-described lower rails 50 and 51 via an upper rail (not shown) so as to be movable in the front-rear direction of the vehicle. The front seat 60 includes a seat cushion frame 61 and a seat back frame 62, and the largest possible deformation load of the tunnel portion 11 is transmitted to the outside in the vehicle width direction through the seat cushion frame 61 to achieve load distribution. It is configured as follows.

  FIG. 8 shows characteristics in which the horizontal axis represents frequency and the vertical axis represents sound pressure, and the difference in sound pressure level between the example (see solid line α) and the comparative example (see dotted line β) was verified. FIG.

  The example shown by the solid line α is the characteristic of the lower body structure of the automobile shown in FIGS. 1 to 7, and the comparative example shown by the dotted line β is one cross at the same position as this example. This is a characteristic of a lower body structure of an automobile in which a member is provided and a lower rail as a seat rail is simply attached to a mounting seat via a bracket.

As is apparent from FIG. 8, the noise of the present embodiment is sufficiently suppressed from the noise of the comparative example in which the opening deformation of the tunnel portion 11 is a sound source (frequency 100 to 200 Hz). It was found that the NVH of the comparative example was worse than that of the present example.
1 to 7, an arrow F indicates the front of the vehicle, an arrow R indicates the rear of the vehicle, an arrow IN indicates an inward in the vehicle width direction, and an arrow OUT indicates an outward in the vehicle width direction.

  As described above, the lower body structure of the automobile of the above embodiment is formed at the tunnel portion 11 formed at the center in the vehicle width direction of the floor panel 10 and extending in the front-rear direction of the vehicle, and at the left and right side portions of the floor panel 10. A vehicle lower body structure comprising left and right side sills 18, 18 extending in the longitudinal direction of the vehicle and left and right center pillars 26, 26 extending from the left and right side sills 18, 18 in the vertical direction of the vehicle. A cross member 35 extending in the vehicle width direction is installed between the side sill 18 in the vicinity of 26 and the tunnel portion 11, and at least a lower portion of the tunnel portion 11 at a position spaced from the cross member 35 in the front-rear direction. Seat rail mounting seats (refer to the front mounting seat 41 and the rear mounting seat 42), and the seat rail mounting seats (mounting seat 41, 2) it is a bottom surface of the seat rail (see the lower rail 50) that rigidly coupled (see FIGS. 1 and 6).

  According to this configuration, one cross member 35 extending in the vehicle width direction is installed between the side sill 18 in the vicinity of the center pillar 26 and the tunnel portion 11, and the weight of the vehicle is reduced by unifying the cross member 35. And the reverse phase of opening deformation before and after the tunnel portion 11 is achieved.

Then, a seat rail mounting seat (front mounting seat 41, rear mounting seat 42) is provided at least at the lower portion of the tunnel portion 11 at a position where the deformation becomes large in the reverse phase, that is, at a position separated from the cross member 35 in the front-rear direction. Since the bottom surface of the seat rail (lower rail 50) is rigidly coupled to the seat rail mounting seat, the anti-phase vibrations before and after the cross member 35 are rigidly coupled to the seat rail mounting seat (mounting seats 41 and 42). Although it works to deform the rail (lower rail 50), the seat rail (lower rail 50) has high rigidity and high yield strength, so that the seat rail (lower rail 50) is not twisted and vibration can be suppressed. .
Accordingly, the seat structure itself can be used without reinforcing the vehicle body itself, and light weight and high rigidity can be enhanced.

  In one embodiment of the present invention, the upper portions of the left and right center pillars 26, 26 are connected to a roof reinforcement 34 extending in the vehicle width direction along the lower portion of the roof panel (see FIG. 1). ).

  According to this configuration, an annular frame structure can be formed by the roof reinforcement 34, the left and right center pillars 26 and 26, and the cross member 35, thereby further strengthening the structure against the torsion of the vehicle body. Can be secured.

  Furthermore, in one embodiment of the present invention, a tunnel reinforcement 16 is provided on the upper surface of the front portion of the tunnel portion 11, and the rear portion of the tunnel reinforcement 16 and the front seat rail mounting seat (front side) are provided. The mounting seat 41 is rigidly coupled (see FIGS. 4 and 6).

  According to this configuration, the tunnel vibration suppression region can be expanded forward of the vehicle by the rigid coupling between the tunnel reinforcement 16 and the seat rail mounting seat (front mounting seat 41).

In the correspondence between the configuration of the present invention and the above-described embodiment,
The seat rail mounting seat of the present invention corresponds to the front mounting seat 41 and the rear mounting seat 42 of the embodiment,
Similarly,
The seat rail corresponds to the lower rail 50,
The present invention is not limited to the configuration of the above-described embodiment.

  As described above, the present invention includes a tunnel portion that is formed at the center of the floor panel in the vehicle width direction and extends in the front-rear direction of the vehicle, and a left and right side that is formed at the left and right sides of the floor panel and extends in the front-rear direction of the vehicle. This is useful for a lower body structure of an automobile provided with side sills and left and right center pillars extending in the vehicle vertical direction from the left and right side sills.

10 ... Floor panel 11 ... Tunnel part
11a, 11b ... sidewalls
11c ... Upper wall
11d, 11e ... Corner 16 ... Tunnel reinforcement 18 ... Side sill 26 ... Center pillar (intermediate pillar)
34 ... Roof reinforcement 41 ... Front mounting seat (seat rail mounting seat)
42 ... Rear mounting seat (seat rail mounting seat)
41a, 42a ... front wall
41b, 42b ... rear wall
41c, 42c ... sidewall
41d, 42d ... upper wall 50 ... lower rail (seat rail)

Claims (3)

A tunnel part formed in the center of the vehicle width direction of the floor panel and extending in the longitudinal direction of the vehicle;
Left and right side sills that are formed on the left and right sides of the floor panel and extend in the longitudinal direction of the vehicle;
A lower body structure of an automobile comprising left and right intermediate pillars extending in the vehicle vertical direction from the left and right side sills,
Between the side sill in the vicinity of the intermediate pillar and the tunnel portion, one cross member extending in the vehicle width direction is installed to be directly joined to the panel-shaped side wall of the tunnel portion ,
A seat rail mounting seat is provided at a lower portion of the side wall which is a lower portion of the side wall below the corner portion of the upper wall of the tunnel portion at a position spaced in the front-rear direction from the cross member,
The seat rail mounting seat has a front wall, a rear wall, a side wall, and an upper wall formed by a member different from the tunnel portion and the cross member, and is formed in a shape opened downward.
The seat rail mounting seat comprises a front mounting seat and a rear mounting seat,
The junction between the tunnel portion of the cross member, spaced forwardly to a position where the mouth apertures closed deformation of the tunnel portion side wall increases, the front mounting locus the tunnel section and the floor spaced apart with the cross member The front mounting seat is joined to the lower part of the side wall that is joined to the panel and is lower than the corner part of the upper part of the tunnel part of the tunnel part , and the mouth opening deformation is larger than that of the corner part. ,
Rear side mounting separated from the cross member by rearwardly separating from the junction of the cross member with the tunnel portion to a position where the opening opening closing deformation of the side wall of the tunnel portion becomes larger in the opposite phase to the front mounting seat. locus is joined to the said tunnel portion and the floor panel, and said lower than the corner portion of the upper wall of the tunnel portion of the tunnel portion, the mouth apertures closed deformation than the corner portion above the front mounting seat opposite The rear mounting seat is joined to the side wall lower portion that becomes larger in phase,
A lower body structure of an automobile in which a bottom surface of a rear end portion of the seat rail is rigidly coupled to face an upper wall of the rear mounting seat. The lower body structure of an automobile according to claim 1, wherein upper portions of the left and right intermediate pillars are connected to a roof reinforcement extending in the vehicle width direction along the lower portion of the roof panel. Tunnel reinforcement is provided on the upper surface of the front part of the tunnel,
The lower body structure of an automobile according to claim 1 or 2, wherein a rear portion of the tunnel reinforcement and a front seat rail mounting seat are rigidly coupled.

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